What are the side effects of L-carnitine?
Mar 09, 2025
Source: Cainiu Health
Dr. Bai Hongmei
Introduction
Under normal circumstances, L-carnitine, as a common nutritional supplement, may help promote fat metabolism and burning. However, excessive or long-term use may lead to a series of side effects. Possible side effects of L-carnitine include reduced sleep quality, malnutrition, muscle weakness and fatigue, neurological problems, and liver or kidney damage.
Generally, the side effects of L-carnitine may include reduced sleep quality, malnutrition, muscle weakness and fatigue, nervous system disorders, and liver and kidney damage. A detailed explanation is as follows:
1. Reduced Sleep Quality
L-carnitine has an excitatory effect. If taken at night or during periods of rest, it may keep the body in an excited state, leading to decreased sleep quality and causing difficulties in falling asleep or frequent awakenings.
2. Malnutrition
L-carnitine may suppress appetite and reduce food intake. Prolonged use may lead to symptoms of anorexia and even insufficient nutrient intake, resulting in malnutrition that can affect normal physiological functions and metabolism.
3. Muscle Weakness and Fatigue
In some cases, L-carnitine may cause muscle weakness or a feeling of fatigue. This may be related to its effect on signal transmission at the neuromuscular junction, or to abnormal energy metabolism in the body.
4. Nervous System Disorders
L-carnitine may stimulate the central nervous system, causing nervous system-related issues such as headache, dizziness, and decreased concentration. These symptoms may interfere with daily life and work.
5. Liver and Kidney Damage
Long-term high-dose use of L-carnitine may cause damage to the liver and kidneys. The liver is a vital organ for metabolism and detoxification, while the kidneys are responsible for excreting waste and toxins from the body. Excessive intake of L-carnitine may increase the burden on these organs, potentially leading to dysfunction or even failure.
When using L-carnitine, it is essential to follow medical advice or the product instructions for proper use and closely monitor your body's response. If adverse symptoms occur, discontinue use immediately and consult a physician. Additionally, L-carnitine should be avoided by pregnant women, nursing mothers, children, and individuals with serious medical histories.
